"One of the things I'm proudest about our leadership is the swift action, not only calling for an immediate Senate investigation, ethics investigation, removing him from his committees, but also sending the signal to him that it was probably best that he resign," Ensign said in an appearance on ABC News' "This Week with George Stephanopoulos." "It was best for himself, best for his family, and best for the institution of the Senate."

Craig announced on Saturday that he will resign effective Sept. 30, 2007. Despite Craig's alleged shock at the Republican leadership's rush to judgment, Ensign stood by his party's actions.

"He had admitted guilt -- guilt to something that I thought was not only embarrassing to himself and his family, but also to the whole United States Senate," said Ensign, who chairs the Republican campaign to take back the Senate.

In a separate interview, 2008 Republican presidential candidate Mike Huckabee agreed with Ensign, saying "one of the things you can admire the Republicans for, they took quick, decisive and, frankly, very effective positions on this."

Huckabee went on to make light of the scandal, showcasing the humor that has served him well in recent weeks on the campaign trail.

"If he had stayed, I think it would have been a very, very challenging environment," Huckabee said. "You might say we would be waiting until the other shoe dropped, which would not be a good situation for the Senate, for Sen. Craig or anybody else for that matter."

Democrat Sen. Charles Schumer, D-N.Y., said that despite the Republican Party actions, the scandal highlights the need for additional ethics reform.

"Everyone knows no party is without its blemishes," Schumer said. "The question is how you react to them.

"What the American people are looking for is not a blame game -- 'Is this party worse than the other?'" Schumer said, "but rather, 'Who is trying to clean it up?'"

Schumer and Ensign also addressed the political fallout of the retirement of Sen. John Warner, R-Va.

Schumer is placing his bet on Virginia Democratic Gov. Mark Warner to replace the veteran senator.

"Mark Warner is an outstanding man," Schumer said. "I've gotten to know him and spend some time with him recently. He's just exemplary. And yes, he'd be our strongest candidate. We hope he will run."

Schumer expressed optimism for Democrats in the 2008 election cycle.

"Our 12 Democratic incumbents, all of them look secure," he said. "Of the 22 Republican seats, there are four that are in blue states."

On the Republican side, Ensign admitted, "This is a competitive election cycle. There's no question. We have 22 seats to defend. The Democrats only have 12 seats to defend. We knew going in that this was going to be a tough election cycle for us."

With Warner's departure, Ensign noted, "It's going to be a tough battle in the state of Virginia to see who represents that state," but expressed hopes that "definitely down in Louisiana, we have a good shot at beating Mary Landrieu."